Electric surfacer



Patented Aug. 23, 1932 g UNITED STATES PATENT OFFICE- SHELDON A.MODGLIN, OF SAN FRANCISCO, CALIFORNIA ASSIGNOR OF ONE HALF TO GEORGE M.COLLINS, OF SAN FRANCISCO, CALIFORNIA ELECTRIC suaraonn Applicationfiled" January 2, 1930. Serial No. 417,936.

This invention relates to surfacing machines as used for grinding,sanding, scraping or polishing of any surfaces which may require suchoperations, and especially to a portable electric driven hand tool whichwill perform a variety of such operations.

The objects of the invention are to rovide such a tool which is smallyet power ul, will grind or otherwise finish a surface on wood or metalwith straight strokes to thus leave a straight scratch finish instead ofthe objectional circular scratches heretofore resulting from suchmachines, also which while of high-speed reciprocatory type will be sub-1 stantially balanced against undue vibration or tendency to crawl alongthe work, and which may readily be adapted to all kinds of work bysimple changing of the surfacing blocks or tools mounted on thereciprocating 20 chucks of the device.

In the drawing accompanying this application Fig. 1 is a side elevationpartly in section showing my improved electric surfacer with a couple ofcutting stones in place ready 25 for operation.

Fig. 2 is a cross section of Fig. 1 as seen from the line 22 thereof.

Fig. 3 is a cross section of a portion of Fig. 2 taken along the line3-3 showing the slid- !0 ing bearings for one of the driving cranks.

Fig. 4 is an enlarged section ofa portion of a slid ng chuck plateengaging at its edge one of the supporting idlers mounted in the channelhousing.

5 The tool is a portable device resembling generally a carpenters planeas seen in Fig.

1 and it is handled in much the same way except that it need merely bepushed or dragged over the workwhile holding it more 0 or loss hightlythereagainst.

The tool comprises a main frame 1 provided with a handle 2 at one endand a knob 3 at the other arranged as on a plane, while on top of theframe within a protective shell 5 4 is a vertical electric motor 5provided with a flexible power cord 6 of any desired length and whichmotor may be switched on and off by a finger of the holding handmanipulating switch buttons 7. The motor is preferably of very highspeed so as to get sufiicient power in small space and weight and it isgeared down by gearmg 8, 9, 10, 11, 12 to two reci rocable chuck plates13, 14 fitted with grin ing blocks 15 which are detachably held in placeas by flanges 16 engaging grooves in the edges of the blocks and securedby screws 17 or in any other desired manner so that other blocks,cutters, scrapers, or polishing blocks, pads, or the like, may besubstituted to suit the character of the work being done.

It will be observed by reference to Fig. 2 that the surfacing or cuttingblocks are in line with the right-hand side of the machine so that aninside corner ma be reached, though if desired the cutting locks may ofcourse extend slightly beyond the right-hand side of the machine, or beof any particular form either at the edges or bottom to fit into anyspecial recess.

The gears are secured to small shafts 18, 19, operating in ball bearingsas indicated and all enclosed between frame plates so that they may berun in soft grease without throwing same about, and also so that thegrindings made by the device will not gain access'to the gears orbearings.

The two reciprocable chucks .13, 14 are spaced endwise in the device andare driven by oppositely set cranks 18, 19 extending from the lower endsof shafts 18, 19 of gears 11, 12 secured thereto. These cranks engageball bearing 22 revolvable and transversely movable i'n ways 24 formingpart of or secured to the upper side ofthe chucks so that in therevolving of the cranks the chucks will be reciprocated lengthwise ofthe tool as the bearings 22 travel back and forth crosswise of thechucks in yoke-like ways 24.

The side edges of the chucks are guided for reciprocable motion by aplurality of vertically disposed grooved rollers 25 pivotally mounted inchann lal ike housings 26 formed with an oven slof ttilong the inner orconfronting sides ,or t he reception of laterally projecting flarlfges27 of the chucks. The slots and flanges aiie formed at an angle as shownbest in Figil i, so that dust and grindings produced by'the machine willtend ,to work out rather than into the roller housings. The housings arealso closed at the ends so that the idlers may be kept packed in softgrease without same being thrown out.

In the drawing the chucks are fitted with coarse grinding blocks 15 suchas carborundum or emery stones, though as suggested, the nature of theblocks, tools, pads, or scratchbrushes used on the chucks will depend onthe work to be done.

In operation, theidevice is held and guided much like a carpenters planeand when the switch 7 is turned on the chucks and grinding blocksreciprocate in opposed relation from the full line to dotted lineposition shown in Fig. 1, and as the device is moved along eitherforwardly or backwardly, a beautifully ground surface is produced freefrom rotary scratches or markings.

I claim:

1. In an electric surfacer having a frame, an electric motor mountedthereon, a chuck plate mounted for reciprocation alongth'e chuck platefor reciprocation,'channelrlike housings along 0 poslte sides of theframe in which said rol ers are mounted provided with an open slot alongconfront ng sides and flanges on said chuck plate extending through theopen slots of the housing engaging the rollers, said flanges extendingat an angle'upward from the vertical sides of said chuck plate and theopposed edges of said slots formed at a corres onding angle to theflange extending theret rough.

SHELDON A. MODGLIN.

- under side of the frame and bearing a rubbing surface, and powertransmission mechanism connecting the motor to said plate arranged forreciprocating the same. a plurality of guide rollers carried by theframe said guide rollers supporting and guiding the chuck plate forreciprocation. channel-like housings along opposite'sides of the framein which said rollers are mounted having confronting walls provided eachwith an open slot there along and flanges on said chuck plate extendingthrough the open slots of the housings engaging the rollers.

2. In an electric surfacer having a frame, an electric motor mountedthereon, achuck plate mounted for reciprocation along the under side ofthe frame and bearing a rubbing surface, and power transmissionmechanism connecting the motor to said plate arranged for'reciprocatingthe same, a pair of channel-like housings inside the frame on oppositesides adjacent the lower edges thereof, said housings having confrontingwalls provided each with an open slot there along, a row of verticallypivoted rollers mounted in each of said housings, each of said rollershaving a horizontal groove intermediate their ends, flanges on saidchuck plate extending through the open slots of the housings and intothe grooves'in the rollers whereby said chuck plate is guided andsupported by the rollers for reciprocation each of the housing walls inconfronting relation overlying the ends of the rollers on opposite sidesof the slot respectively.

3. In an electric surfacer having a frame, an electric motor mountedthereon, a chuck plate mounted for reciprocation along the under side ofthe frame and bearing a rubbing surface, and power transmissionmechanism connecting the motor to said plate arranged reciprocating thesame, a plurality of guide rollers carried by the frame, said guiderollers supporting and guiding the

